<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>read_until (9 of 16 overloads)</title>
<link rel="stylesheet" href="../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../index.html" title="Asio">
<link rel="up" href="../read_until.html" title="read_until">
<link rel="prev" href="overload8.html" title="read_until (8 of 16 overloads)">
<link rel="next" href="overload10.html" title="read_until (10 of 16 overloads)">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload8.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload10.html"><img src="../../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.read_until.overload9"></a><a class="link" href="overload9.html" title="read_until (9 of 16 overloads)">read_until (9
        of 16 overloads)</a>
</h4></div></div></div>
<p>
          Read data into a streambuf until it contains a specified delimiter.
        </p>
<pre class="programlisting">template&lt;
    typename <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a>,
    typename Allocator&gt;
std::size_t read_until(
    SyncReadStream &amp; s,
    asio::basic_streambuf&lt; Allocator &gt; &amp; b,
    char delim);
</pre>
<p>
          This function is used to read data into the specified streambuf until the
          streambuf's get area contains the specified delimiter. The call will block
          until one of the following conditions is true:
        </p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
              The get area of the streambuf contains the specified delimiter.
            </li>
<li class="listitem">
              An error occurred.
            </li>
</ul></div>
<p>
          This operation is implemented in terms of zero or more calls to the stream's
          read_some function. If the streambuf's get area already contains the delimiter,
          the function returns immediately.
        </p>
<h6>
<a name="asio.reference.read_until.overload9.h0"></a>
          <span><a name="asio.reference.read_until.overload9.parameters"></a></span><a class="link" href="overload9.html#asio.reference.read_until.overload9.parameters">Parameters</a>
        </h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">s</span></dt>
<dd><p>
                The stream from which the data is to be read. The type must support
                the SyncReadStream concept.
              </p></dd>
<dt><span class="term">b</span></dt>
<dd><p>
                A streambuf object into which the data will be read.
              </p></dd>
<dt><span class="term">delim</span></dt>
<dd><p>
                The delimiter character.
              </p></dd>
</dl>
</div>
<h6>
<a name="asio.reference.read_until.overload9.h1"></a>
          <span><a name="asio.reference.read_until.overload9.return_value"></a></span><a class="link" href="overload9.html#asio.reference.read_until.overload9.return_value">Return
          Value</a>
        </h6>
<p>
          The number of bytes in the streambuf's get area up to and including the
          delimiter.
        </p>
<h6>
<a name="asio.reference.read_until.overload9.h2"></a>
          <span><a name="asio.reference.read_until.overload9.exceptions"></a></span><a class="link" href="overload9.html#asio.reference.read_until.overload9.exceptions">Exceptions</a>
        </h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">asio::system_error</span></dt>
<dd><p>
                Thrown on failure.
              </p></dd>
</dl>
</div>
<h6>
<a name="asio.reference.read_until.overload9.h3"></a>
          <span><a name="asio.reference.read_until.overload9.remarks"></a></span><a class="link" href="overload9.html#asio.reference.read_until.overload9.remarks">Remarks</a>
        </h6>
<p>
          After a successful read_until operation, the streambuf may contain additional
          data beyond the delimiter. An application will typically leave that data
          in the streambuf for a subsequent read_until operation to examine.
        </p>
<h6>
<a name="asio.reference.read_until.overload9.h4"></a>
          <span><a name="asio.reference.read_until.overload9.example"></a></span><a class="link" href="overload9.html#asio.reference.read_until.overload9.example">Example</a>
        </h6>
<p>
          To read data into a streambuf until a newline is encountered:
        </p>
<pre class="programlisting">asio::streambuf b;
asio::read_until(s, b, '\n');
std::istream is(&amp;b);
std::string line;
std::getline(is, line);
</pre>
<p>
          After the <code class="computeroutput">read_until</code> operation completes successfully, the
          buffer <code class="computeroutput">b</code> contains the delimiter:
        </p>
<pre class="programlisting">{ 'a', 'b', ..., 'c', '\n', 'd', 'e', ... }
</pre>
<p>
          The call to <code class="computeroutput">std::getline</code> then extracts the data up to and
          including the newline (which is discarded), so that the string <code class="computeroutput">line</code>
          contains:
        </p>
<pre class="programlisting">{ 'a', 'b', ..., 'c' }
</pre>
<p>
          The remaining data is left in the buffer <code class="computeroutput">b</code> as follows:
        </p>
<pre class="programlisting">{ 'd', 'e', ... }
</pre>
<p>
          This data may be the start of a new line, to be extracted by a subsequent
          <code class="computeroutput">read_until</code> operation.
        </p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2018 Christopher M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload8.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../read_until.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload10.html"><img src="../../../next.png" alt="Next"></a>
</div>
</body>
</html>
